The reaction of one equivalent of hydrogen bromide with 1,3-butadiene gives different products at under different conditions:1
The addition of hydrogen chloride also gives rise to similar products.2 ...

If we make a resonance structure for the anilinium ion, with positive charge at either the ortho or the para position, we get a pentavalent nitrogen, which is not possible. So, how is the $\ce{-NH3+}$ ...

Cyclohexenone, an α,β-unsaturated ketone, is electrophilic at both the carbonyl carbon, as well as the β-carbon. So, it can either undergo 1,2-addition to give the allylic alcohol 1, or 1,4-addition ...

In the azo coupling of aniline with benzenediazonium cation, I thought of two possible products 1 and 2 that could be formed. However, I can't work out which will be preferred. What would be the major ...

In Phil Baran's lectures on heterocyclic chemistry at Scripps, one of the lecture problems is concerned with this synthesis of Vioxx:
The first step supposedly involves an anti addition of the aryl ...

Para-terphenyl: it doesn't look pretty with all those math-y numbers, but those are going to come helpful in answering my question!
A question asked me to tell the expected product when this reacts ...

I am supposed to work out which product is formed in which solvent when naphthalen-1-olate is treated with benzyl iodide.
DMSO is a polar aprotic solvent, as it does not possess an acidic hydrogen. ...

Secondary allylic halides can be produced in high yield with the following Mitsunobu-type reaction:[1]
The yield being $94~\%$.
The last step in the mechanism is:
Why is the $\mathrm{S_N2}$ reaction ...

In my Chemistry class, we were given this question to solve, and I'm not sure I fully understood the solution.
I understand that since the substrate is bulky, Saytzeff elimination can't happen, so it ...

I am supposed to rationalise the regioselectivity of bromination of 8-chloroimidazo[1,2-a]pyrazine, as depicted in the scheme.
The left ring kind of looks like a pyridazine. If it's anything like a ...

I am supposed to find the product of the following reaction:
I know that six-membered rings are more stable than five-membered rings, but the C-D bonds are stronger, so it confuses me where will the ...

Sulfonyl azides, $\ce{RSO2N3}$, are capable of acting as sources of electrophilic azide ("$\ce{N+3}$"), but are also capable of effecting diazo transfer, as shown in the scheme below, taken from ref 1:...

I am trying to predict the products of both the hydroboration/oxidation and acid-catalyzed hydration of 1-phenylpropene:
Both C1 and C2 of the double bond are secondary carbons. However, I have the ...

In nucleophilic aromatic substitution (SNAr) reactions on pyridines, displacement of leaving groups at C-2 and C-4 is favoured because the negative charge in the intermediate can be delocalised onto ...

When discussing the Gattermann–Koch reaction on phenol substrates, it has been said that O-acylation is a problematic competing reaction as
in a phenol, there's high electron density on the O atom [...

Which is the major and minor product formed from the reaction of benzyl methyl ether with dinitrogen pentoxide?
I know that $\ce{NO2+}$ is behaving as an electrophile here and attacking the aromatic ...

The mechanism of electrophilic addition on alkenes often involves an electrophile attacking the double bond and causing an electromeric shift of electrons. The electrophile then forms a bridged cation ...

Normally, according to Baldwin's rules, 3-exo to 7-exo cyclisations are preferred over endo cyclisations. But in the following example, a 7-endo-trig reaction is favoured over a 6-exo-trig and I am ...

I am working with N-tosyl-2-piperidone and attempts to use the lithium enolate of this compound to perform an nucleophilic acyl substitution reaction on an several chloroformate esters in THF has lead ...

Why does the Ziegler–Natta polymerization display the regioselectivity shown in the image? Internal nucleophiles (coordinated to the metal) should attack the alkene on the less substituted end, like ...

In the intramolecular aldol condensation of hexane-2,4-dione (above), why does the base abstract one of the $\ce{-CH3}$ protons instead of one of the $\ce{-CH2}$ protons? Both sets of protons are α to ...

In the last step of the iodolactonisation of 3,3-dimethylpent-4-enoic acid,[1,2] why does the carboxylate attack the iodonium to form a 5-membered ring, when a more stable 6-membered ring is possible? ...

(a) Why would cyclohexane expand into cycloheptane? Cyclohexane is stable.
(b) Why would cyclopentane not ring expand into cyclohexane? In the process a tertiary carbocation would be formed just like ...